Alnus serrulata

Common Name(s):

Hazel alder, Smooth alder, Tag alder

Categories:

Native Plants, Trees

Comment:

Alnus serrulata, commonly called tag alder, smooth alder or hazel alder, is a multi-stemmed, suckering, thicket-forming, large deciduous shrub or small tree that typically grows to 10-20’ tall. It is most often seen in a multi-trunked form with a densely branched crown. It is native to boggy ground along streams/lakes/rivers, wetland margins, springs, spring-fed meadows, ditches and swampy fields from Nova Scotia to Illinois and Missouri south to eastern Texas and northern Florida.

Wildlife Value: This plant is highly suseptable to damage from deer. Harvester butterfly eat the aphids commonly found on alder. White-tailed deer browse the foilage. Birds and small mammals eat the pollon rich male flower clusters in the spring.

Insects, Diseases, or Other Plant Problems: Canker can be severe on the Tag alder. Powdery mildew and leaf curl may also appear. Watch for aphids, leaf miners, tent caterpillars, lace bugs and flea beetles. Chlorosis will occur in high pH soils.

Height:

15-20 ft.

Flower:

The flowers of the Tag alder are monoecious (separate male and female flowers on the same tree), appearing in separate catkins in March-early April before the leaves emerge. Male catkins (brownish-yellow flowers) are slender, cylindrical and droop in clusters of 2-5 from near the branch tips to 2-4" long. Female catkins (bright red flowers) are upright cylinders (to 1/4" long) located at the twig tips in clusters of 2-5. Female flowers are pollinated by wind. Female catkins develop into 1-inch long fruiting cones (strobiles) to 3/4” long containing winged nutlets (seeds). Fruiting cones mature to dark brown in fall, with persistence into winter. Cones have woody scales and resemble small pine cones. Birds feed on the seed.

Zones:

5-9

Habit:

Deciduous

Site:

The Tag alder is best grown in medium to wet soils in full sun to part shade. It will tolerate mucky soils. This tree will not grow well in full shade. It is winter hardy to UDSA Zones 4-9.

Texture:

Medium

Form:

Multi-stemmed

Exposure:

Full sun, part shade

Fruit:

Cones

Width:

8-15 ft.

Leaf:

The Tag alder has broad elliptic to obovate, alternate, simple dull green leaves (2-4" long) with serrulate margins are wedge-shaped at the base and pointed at the tip. This tree has insignificant fall color.